Rax70 having trouble communicating with webiste

I am not sure the Router is my problem, but I have tried everything that has been suggested.  I am getting http error code 99 socket code 0 which I was told is a communication problem.

I am using a program, Auction Wizard 2000,  to upload data to ebay.  This lists items, uploads photos,  updates sold items and creates invoices.    It usually takes minutes to upload and took 10 hours over the weekend.   This started last week sometime.  I have checked for updates with that program and have contacted them.  No one else is having problems. 

I saw there was a windows update Sept 11th so I uninstalled that.  No difference.

Called the cable company.   No help.

Updated the router firmware.  Still the same very slow process.

Using Windows 11 and their security programs.  No VPN.  

I tried another computer on the same network, same issue.  

Anybody have any suggestions?

Thank you so much!

Karen